1. Field of the Invention
The present invention relates to magnetic kinetic amusement devices wherein there is an intermittent interchange of motional energy between dynamic components by magnetic interactions.
2. Description of Prior Art
A variety of magnetic amusement devices and kinetic sculptures are known. In such devices, movable members are magnetically attracted or repelled by magnets on adjacent units to provide suspensory or motion effects. Often the objective is eye appeal, as for display purposes. For example, in the display apparatus of the Littlefield U.S. Pat. No. 3,196,566 a model airplane is suspended in air by magnetic repulsion between a magnet in the model and two spaced magnets in an underlying stationary base.
Other devices are characterized by magnetically imparted motion. Thus in the U.S. Pat. No. 2,220,049 to Dunmore, a pendulum-suspended figure is provided with a magnet that coacts with another magnet mounted below a platform. The sub-platform magnet may be fixed at a location offset from the pendulum rest axis, or may be driven through a circular or irregular path in a plane parallel to but beneath the platform. The suspended figure swings and rotates in some more or less random pattern under magnetic influence.
The magnetic amusement device of MacPherson (U.S. Pat. No. 3,550,316) uses a pair of pivotally supported, balanced rods each having a magnet at one end and a counterweight at the other end. Due to magnetic interaction, when one rotor is spun gently, rotation is imparted in the opposite direction to the other balanced rod. Depending on the speed of rotation, the interaction of the magnetic fields may result in the transfer of inertial energy as the magnet ends pass adjacent to each other causing changes in speed and sometimes reversal of direction of rotation.
In the Podesto kinetic sculpture of U.S. Pat. No. 3,609,606 a pair of magnets are attached to the free ends of a pair of artistically shaped spring wires that extend from a base. Repulsion between the magnets imparts random, tremor-like motion to the springs.
In the magnetic kinetic amusement device of Jacobson (U.S. Pat. No. 4,011,674) an embodiment includes magnetically interacting elements comprising pendulums each having at the pendulum end a design member containing a magnet. The plural pendulums may be disposed in a three dimensional array, or may be suspended from a common support with the magnets aligned for mutual repulsion so that the pendulums assume a conical arrangement. Displacement or rotation of any pendulum design member causes energy exchange through magnetic interactions.
The magnetic kinetic amusement device of Samson (U.S. Pat. No. 5,026,314) includes a supporting structure having side pieces which pivotally support rigid suspending elements each having a permanent magnet at its lower end. The magnets are arranged in a row, such that they will repel the next magnet in the row, the motion of the magnets being constricted to swinging in the vertical plane containing the row. As two adjacent magnets swing through an arc, they do not remain face to face but become more and more offset as they swing. There may be a point in the arc (depending on the dimensions) where they are approximately edge to edge and no longer repelling each other, but instead problematically drawn together by an attraction causing all motion to terminate. The resting position of the magnets is principally determined by gravity, thus when a magnet is set in motion it continues to swing back and forth until it eventually is at rest in a vertical position. This dynamic interplay between the forces of gravity and the magnetic fields of the magnets quickly leads to chaotic motion where all the magnets are swinging back and forth and irregularly repelling each other, i.e., the period of oscillation of each magnet changes often and in a seemingly random fashion that could be described as somewhat nervous.
Objects and Advantages
An object of the present invention is to provide magnetic kinetic amusement devices in which there is a continuing, but intermittent exchange of coherent motional energy between dynamic members, accomplished by magnetic interactions. The dynamic members radiate from a common fulcrum arranged similar to spokes on a wheel that radiate from a hub. This arrangement insures that, 1) the magnets will always be aligned face-to-face when they approach each other, maintaining and maximizing the repelling force; and 2) the resting position of each magnet will be determined more by the magnetic fields of the adjacent magnets than by gravity, resulting in more coherent motion. This motion may be such that the viewer is able to observe a compression wave traveling transversely along the series of magnets, reversing directions at the end of the series, and continuing on in this fashion with minimal degeneration into chaotic motion. The transfer of motion between magnets occurs with minimal sound and is much quieter than actual collisions between objects such as spheres, and thus less noise disturbance would result in areas, such as a work office, where a quiet atmosphere is maintained. The participant is able to initiate motion in many ways, and the resultant motional effects are fascinating to view. This invention, in demonstrating virtual collisions (the magnets do not actually touch), compression waves, oscillation, magnetism, and the gradual degeneration of kinetic energy into thermodynamic energy, may also prove to be a valuable teaching tool for physics students.